it would have been hanging from that string as a weight. correct. right. so that was very clear that that bolt was in fact part of our device that was described in the letters. reporter: and there were fragments of a plastic soda bottle, black paint still clinging to it again just like the diagram. there was a spring that was similar to a rat trap spring. there was gasoline on the victim s clothing. that we were able to determine that had no business being in that panel. reporter: so if you found the writer of those letters you had found your killer. that was our opinion. yes. reporter: along with the diagram was a second letter in which the bomber repeated his earlier claim that he was a reluctant assassin. after a career of killing he wrote, i wanted to save a life before i take my life. the bomber repeated his warning. roberto s brother eduardo was next.
fishing string attached just under the head of the bolt which was how it was depicted in the diagram. it would have been hanging from that string as a weight. correct. right. so that was very clear that that bolt was in fact part of our device that was described in the letters. reporter: and there were fragments of a plastic soda bottle, black paint still clinging to it again just like the diagram. there was a spring that was similar to a rat trap spring. there was gasoline on the victim s clothing. that we were able to determine that had no business being in that panel. reporter: so if you found the writer of those letters you had found your killer. that was our opinion. yes. reporter: along with the diagram was a second letter in which the bomber repeated his earlier claim that he was a reluctant assassin. after a career of killing he wrote, i wanted to save a life before i take my life.
almost as someone sent us a cover to the box. they matched the bits to the diagr diagram. the first thing i looked for was the bolt. there it was. the thing that made it exceptionally clear was the fact the bolt still had some fishing string attached just underneath the head of the bolt which is how it was depicted in the diagram. so it would have been hanging from that string? correct. as a weight? right. and so that was very clear that that bolt was, in fact, part of our device that was described in the letters. and there were fragments of a plastic soda bottle. black paint still clinging to them. again, just like the diagram. there was a spring that was similar to a rat trap spring. there was gasoline on the victim s clothing. and then we recovered pieces of a 9 volt battery that we were able to determine that had no business being in that panel. so if you found the writer of those letters, you had found your killer. that was our opinion, yes.